1. Field of the Invention
This invention relates generally to wheel suspensions, and more particularly to a self-suspending wheel with a shock absorbing element contained within the center of the wheel itself.
2. Description of Related Art
The following art defines the present state of this field:
Gagnon, et al., U.S. Pat. No. 5,305,496 describes a caster with two spaced apart wheels with an elastomeric torsional shock and vibration isolating suspension between them. The wheel axis is spaced longitudinally from a bearing axis to subject elastomeric disks positioned between the wheels to torsional shear stresses to help absorb shocks and vibrations. A snubber is provided for limiting the angular motion of the wheels about a bearing axis.
Braeger, et al. U.S. Pat. No. 5,394,589 describes three embodiments of a shock-isolating caster. A surface-effect damper engages at least one of a wheel element and an intermediate structural member to dampen vibration and shock loads which would otherwise be transmitted from the wheel element through the intermediate structure and mounting member to the equipment supporting cart. A first embodiment positions the damper between an outer wheel rim and an inner wheel hub. Second and third embodiments mount the wheel on a pivotable arm and dampen the movement of the arm. Capability to adjust damping levels is provided.
Kindstrand, et al., U.S. Pat. No. 5,493,755 describes a caster with a stationary hub having a bearing between the hub and a floor engaging wheel ring which allows the wheel ring to rotate relative to the hub. Torsional elastomeric elements mount the hub between spaced support arms radially inward of the bearing and are positioned eccentrically relative to the axis of rotation of the wheel ring so as to suspend the hub resiliently between the arms. In an alternate embodiment, the hub is cantileverd from a single support arm.
Lazarevich, et al., U.S. Pat. No. 5,704,621 describes a suspension system for an in-line roller skate in which the suspension system independently controls each wheel of the skate. The suspension system components for each wheel includes a swing arm that is pivotally mounted to a frame attached to a boot of the skate. The wheel is rotatably mounted on a rotation axle between opposing legs of the swing arm. Two C-shaped spring stays are secured to opposing side rails of the frame where one leg of each spring stay travels through a stand-off rigidly secured to one of the opposing legs of the swing arm. A helical spring surrounds the leg of each spring stay between the stand-off and the frame. When the wheel encounters a bump in the ground terrain, the swing arm pivots up and the helical springs are compressed between the stand-off and the frame providing shock absorption. A rebound a stop prevents the swing arm from pivoting too far downward. A jounce stop prevents the swing arm from pivoting too far upward.
Gray, U.S. Pat. No. 4,403,784 describes a roller skate formed of a plate with an upper surface to receive a shoe and having a forward and rearward downwardly extending suspension housing, each housing having an opening therethrough, an axle extending through each suspension housing opening having a means at each end for receiving a skate wheel, a first and second elastomeric member received in each suspension housing in spaced apart relationship, each of the elastomeric members having an opening receiving the axle, bolts extending through threaded openings at the top of the suspension housing, the ends of the bolts engaging the upper surfaces of the elastomeric members so that the compressive force applied by the elastomeric members to the axle may be adjusted by threadably positioning the bolts. Another arrangement includes each axle in two portions hinged in the middle so that each roller skate wheel is independently resiliently supported relative to the skate body.
Hager, U.S. Pat. No. 4,685,174 describes a shock absorbing caster wheel in which the wheel support bracket is pivotally mounting on a caster bracket and a spring engages the wheel support bracket and caster bracket to absorb shocks on the caster wheel. Vibration dampening pads on the caster bracket slidably engage wall surfaces on the wheel support bracket to dampen oscillation of the wheel support bracket.
Burns, U.S. Pat. No. 5,823,543 describes a roller skate shock absorber system in at least two double pivot mechanisms spaced longitudinally from front to back along a skate shoe; a truck device including a plurality of wheels interconnected with the double pivot mechanisms; each of the double pivot mechanisms including a first pivot mounted to the skate shoe, a pivot member rotatably connected to the first pivot and having a second pivot rotatably attached to the truck device; and at least one resilient member dispose between the skate shoe and the truck mechanism for biasing at least one of the pivot mechanisms with its first and second pivots generally vertically aligned to provide a firm push-off force.
Hopkins, U.S. Pat. No. 1,185,098 describes a vehicle wheel with a central hub box providing a pair of spaced thrust disks, a hub casing providing conical ends, annular members provided with inclined portions for wedgingly engaging within said conical casing ends, each annular member comprising a bearing flange for engaging the corresponding thrust disk and a cylindrical container, and cushioning members positioned in said cylindrical containers in engagement with said hub box.
Bourdeau, U.S. Pat. No. 5,393,078 describes a skate including a chassis formed by an upper horizontal plate solidly joined to the sole of a shoe by fasteners and a lower part running perpendicular to the plate and including at least one lateral flange on which the wheels are disposed by transverse axles solidly joined to the chassis, constituting a rolling train, each of the wheels having a hub in fixed rotation, which is disposed on the axle and which supports a bearing interpolated between the hub and a tire. The hub of the wheel is equipped with an arrangement which allows for its angular deflection relative to its median horizontal plane. The arrangement for angular deflection includes the transverse axle which is horizontally off-center in relation to the virtual center of the wheel which can cooperate by abutment with a fixed axle solidly joined to the chassis which passes through it, and which supports an elastic recoil device.
Henschen, U.S. Pat. No. 5,411,287 describes a torsion axle for a vehicle including an elongated axle tube enclosing first stage torsion shafts and second stage torsion shafts all having a common axis, and a metal tube or a non-circular portion of the axle tube and a plurality of resilient rubber rods confine each of the shafts for torsionally resisting rotation of the shaft. Each first stage metal tube is secured to the surrounding axle tube, and each second stage metal tube is connected to the corresponding first stage shaft. A stud projects outwardly from each second stage metal tube through a slot within the surrounding axle tube to limit rotation of the second stage tube with the first stage shaft, and a crank arm and eccentric spindle are secured to the outer end portion of each second stage shaft for receiving a wheel. In modifications, the first stage shafts for both the left and right wheels are connected as one shaft, and a hydraulic winch cable and spool provide for pre-rotating the one shaft or the axle tube to lower and raise the vehicle.
Bekessy, U.S. Pat. No. 5,573,309 describes an in-line roller skate wheel and truck in which an elongated truck frame with a pair of spaced longitudinal side rails mount a plurality of roller wheels. At least one of the roller wheels has a hub core with a coaxial tire receiving shoulder. A tapered tire deflection controlling rim extends circumferentially about the shoulder, with rim side walls extending radially outward from a wide base at the tire receiving shoulder to a narrow peripheral surface. An annular resilient tire is mounted to the hub, engaging the tire receiving shoulder and encasing the tapered tire deflection controlling rim. The tire includes an annular ground engaging surface section and an annular high friction shoulder situated radially inward and axially outward of the ground engaging outer surface. The rim and tire configuration aid in maximizing speed and control in turns. Another one of the in-line roller wheels, situated at the heel end of the truck includes a tire of a slightly reduced diameter and is formed of a resilient material with a hardness value greater than the remaining tires on the truck. It also includes recessed braking dimples on its ground engaging surface to aid in approximating heels-forward "skid" stopping in a manner similar to stopping methods used by ice skaters.
Berges, FR2676397-A1 describes an integrated suspension wheel and shock absorber formed from a rigid rim which supports a tire. Four rings of cylindrical form join the rim to the hub. Paddle blades located radially between the suspension rings increase transmission of the torque. The rings serve progressively as shock absorbers. They are made of composite synthetic material having an elasticity calculated as a function of the required suspension. The material which fixes the rings to the rim and to the hub is a mono- or multi-component polyurethane.
Shepherd's Complete Specification, A.D. Dec. 21, 1896, No. 29,276. This reference was provided by the United States Patent and Trademark Office during prosecution of the parent case of this CIP.
The prior art teaches shock absorbers placed along a skate shoe, on a castor bracket, in a skate suspension housing, in a boot of a roller skate, in a hub cantilevered from an exterior support arm, and in other applications, as for instance, within a bicycle wheel hub. However, the prior art does not teach that the shock absorbing means may be fitted within the hub of the wheel with merely a single axle attached to a frame, to provide a highly compact and inexpensive shock system. The present invention fulfills these needs and provides further related advantages as described in the following summary.